My exmark wb has a 20 horse kohler on it. I noticed last season that the battery seemed to loose power at the end of the day.(new battery) The starter takes energy at start up and the electric clutch also takes a little energy. I assume that the charging system on the Kohler can still keep the battery up while i am mowing. Should i let the engine run for a few minutes to charge the battery after i have mowed? It is possible that i have a bad battery or a dragging starter but all the connections are good. I will try another new battery but what if it keeps doing this?